As is known, closed cycles gas turbine power plants consist of a heat source, a compressor, a gas turbine and a heat exchanger for cooling the work gas in the cycle. The hot gas having performed work in the gas turbine and exhausted therefrom is cooled by the heat exchanger is preparation for being recompressed and recycled. Such gas turbine power plants of the closed cycle type may be complemented with further coolers, if necessary, in which the gas will be cooled between individual compressor stages while being compressed. Moreover, it is possible to employ recuperators which serve to convey the heat of exhaust gases partly to the compressed working gas.
Power plants with gas turbines which work in closed cycles are particularly preferable where the nature of the heat source permits heat transmission between heat source and gas only through heat exchangers. Combustion of solid combustibles, nuclear reactors or the like may be cited as examples. The temperature limits of the cycles which are performed in power plants with closed cycle gas turbines will naturally be selected according to various technical and economical conditions. If such conditions should be met with, the abduction of waste heat of the cycle would very often occur at temperatures which are considerably higher than the ambient temperature. This can occur e.g., if compression takes place without intermediate cooling and/or too high temperature differences prevail in a recuperator which is intended to return a part of the heat content of the work gas after compression has taken place. Such high temperature differences are due to insufficient recuperator surfaces which, in turn, result from lack of space. Such may be the case e.g. where nuclear reactors are accommodated in prestressed concrete reactor vessels for safety reasons.
If the heat of the work gas is abducted at a relatively high temperature, the exploitation of energy which is latent in the temperature differences referred to above is already justified.
The invention aims at exploitation of such energy.